On account of their compactness and cost-effective production, semiconductor lasers find application in numerous areas of application such as, for example, data transmission, data storage, projection, material processing, optical pumping, biosensor technology and the like. Semiconductor lasers based on the AlInGaN material system, in particular, afford diverse possibilities for use on account of their generated radiation in the UV to blue or green wavelength range. In most fields of application, a high optical output power or output power density of the semiconductor laser is of importance in this case.
However, in the case of semiconductor lasers, the output power is limited on account of thermal effects. By way of example, in the case of so-called “single emitters”, the output power is limited to a few hundred milliwatts in cw-operation.
Optical output powers can be increased, inter alia, by increasing the efficiency of the semiconductor laser, for example with the aid of an optimized epitaxy design of the layers of the semiconductor laser. However, in this case, too, the output power of semiconductor lasers of this type is limited to a few hundred milliwatts in cw-operation on account of thermal effects.
Power-increasing measures can furthermore be made possible for example by simultaneous operation of a plurality of laser diodes.
In addition, in the case of broad stripe lasers, as a result of the so-called “thermal lens”, which constricts the laser mode of the laser to a few μm at high currents, there is the risk of the ridges arranged at the top side being damaged or even destroyed at high current densities.